The Mistake
by Bi-Winning
Summary: PB was just testing potions with Finn, but one of them turned Finn into a justice-craved lunatic who kills those who are evil, even if it was only their past. Rated M for violence. I don't own adventure time.


PB was, unsurprisingly testing new formulas inside her lab at the candy palace. She was attempting to make some agility and intelligence potions, as she found her candy citizens to be quite slow, both intellectually and physically.

Finn was standing by as a test subject and assistant due to his devotion as a hero to assist monarchs whenever possible.

"Finn, try this" PB said as she handed him a vial of purple liquid. She really should have tested it on some animals first, but due to how persistent he was to help.

Finn drank the vial while PB's master computer scanned him.

"Testing for agility…6.8% increase. Testing for intelligence…3.2% increase." stated the computer.

"Darn, these effects are not strong enough or long term enough to help my people. That's why, for this next test, I will be using several superheavy elements including element 111, 113, 115 and 117. Finn, are you sure you will be willing to test this?" the princess said worriedly.  
"It is my sworn duty as hero to that which you command, Bubblegum" Finn said.

"Very well" she sighed.

Finn drank this new black vial, but this potion was far different from the others because he immediately got on his knees and clenched his head with his hands while screeching.

"Warning! 111 effects: Agility increase… 343%! 113 effects: Brain capacity increase…598%! 117 effects: Strength increase… 842%! Specimen unstable!"

Finn fell to the ground, lifeless. PB rushed to his side "FINN!"

The computer spoke one last time. "Attention. New element ununpentium is taking effect. Revival imminent. Retaining other elemental builds."

Finn rose in the air, his current body changing shape. He was now 9 feet tall, his skin looked like charcoal as if though he recently swam in lava, his eyes glowed a bright shade of orange and his clothes were torn up.

"RAHHHHHHHHHHHHHHHHHHHH" Finn screamed.

"F-F-Finn?" PB said terrified while slowly backing away.

"I AM NOT FINN! I AM THE JUSTICE OF THIS WORLD AND I SEE YOUR SINS!" Finn roared as he pulled PB in and broke her neck in half, decapitating her.

Finn then proceeded to eat every last bit of PB, even her hard candy bones. As he did, he could feel himself becoming stronger and more intelligent.

Just then, Finn's increased hearing told him that Peppermint butler was coming up the stairs. Finn hid next to the door hinges and waited to strike.

The door creaked open. "Princess? I heard some noise, are you alrigh-"

Those were Peppermint's last words before the top half of him was bitten off by Finn.

"I must leave and destroy other unjust people of this world" he thought as he leaped out the window, although his extreme build annihilated the whole wall.

He landed on his feet, behind the palace and busted the candy kingdom wall down by kicking it.

Then, a voice entered his head as he ran off towards the Grasslands. "Well done, my son. You have done well."

"Who are you?"

"Refer to me as Davidson. I am a spirit of a past human; I used to be one of you. I will guide you on your journey to liberate this land from the sinful. For now, I give you these gifts to help you. To your right, you will see your faithful hellhound named Yersd. He will attack your enemies and will alert you when a presence is near. To your left, you will see your mount whom is a primal alien who was sent here years ago name Lors."

Sure enough, to his Finn's left, he could see a dog that had skin red enough and charred enough that he seemed he could burst into fire at any moment. It was about 2 feet tall and 3 feet long with red eyes.

To Finn's left, he could see the alien who was the size of a rhinoceros and had enough armor to cover a tree. Whatever wasn't covered by armor was a deep shade of orange, except for its skull.

"Who is the next target, David?" Finn asked anxiously.

"A wizard named Ash who lives in the woods. Do you know him?"

"Yes, and I will ensure he suffers."


End file.
